Touch sensing or touch position detection technology capable of providing a natural interface between an electronic system and user has found widespread applications in a variety of fields, for example, in mobile phones, personal digital assistants (PDAs), automatic teller machines (ATMs), game machines, medical devices, liquid crystal display (LCD) devices, light emitting diode (LED) devices, plasma display panel (PDP) devices, computing devices, and the like, where a user may input desired information and/or operate the electronic system through a touch sensing device associated with the electronic system. A touch sensing device typically includes a detecting unit, a sensing circuit having a plurality of touch sensors and a network of control lines electrically connecting the plurality of touch sensors to the detecting unit, and a touch panel associated with the plurality of touch sensors.
FIG. 4 shows a conventional touch sensing device 10 having a sensor array 1 and detecting unit 2 including a plurality of differential amplifiers 3-8. The sensor array 1 includes a plurality of x-axis sensing electrodes, x1, x2, . . . , x6, and a plurality of y-axis sensing electrodes, y1, y2, . . . , y6, arranged in a matrix form. Each two sensing electrodes are coupled to a single differential amplifier, which is adapted for amplifying the potential difference, developed by touching, between the two corresponding sensing electrodes. Based on the amplitude of the sensed signal, the touch position is determined. However, for such a configuration of the touch sensing device, the sensed signal of a touch is amplified by a single differential amplifier. Accordingly, the sensitivity of the touch sensing device is limited.
Therefore, a heretofore unaddressed need exists in the art to address the aforementioned deficiencies and inadequacies.